1. Field
Exemplary embodiments of the present invention relate to a latch circuit storing a signal or a data, and more particularly, to a technology for improving an initialization operation of a latch circuit.
2. Description of the Related Art
A latch circuit, which is a circuit storing a signal or a data has been commonly used for integrated circuits.
FIG. 1 is a circuit diagram illustrating a latch circuit in accordance with the related art.
Referring to FIG. 1, the latch circuit includes two inverters I11 and I12 of which the input/output terminals are interconnected and an initialization unit 110.
When a ‘high’ level signal is applied to an input node IN, the inverter I11 drives an output node OUT at a ‘low’ level and the inverter I12 drives the input node IN at a ‘high’ level in response to a level of the output node OUT. Further, when a ‘low’ level signal is applied to the input node IN, the inverter I11 drives the output node OUT at a ‘high’ level and the inverter I12 drives the input node IN at a ‘low’ level in response to the level of the output node OUT. The inverters I11 and I12 continue to hold and store the level of the signal (data) input to the input node IN according to the principle.
The initialization unit 110 drives the input node IN at a ‘low’ level when the initialization signal INITIAL is activated to initialize a value stored in the input node IN of the latch to a ‘low’ level.
When the input node is activated at a ‘low’ level by the initialization signal INITIAL under the situation in which the ‘high’ level data is stored in the input node IN of the latch and the ‘low’ level data is stored in the output node OUT, a conflict that the inverter I12 drives the input node IN at a ‘high’ level and the initialization unit 110 drives the input node IN at a ‘low’ level occurs. The conflict causes concerns in that it may become difficult to perform the initialization of the latch, and a current path through a pull up element (generally, PMOS transistor) in the inverter I12 and the initialization unit 110 is formed to consume a large amount of current.